FUEL CELL SYSTEM AND HOT WATER STORAGE UNIT FOR FUEL CELL SYSTEM

To avoid occurrence of an uncontrollable state of heating capacity by suitably controlling during the time when hot water circulation operation and heater heating operation are conflicting.SOLUTION: In a fuel cell system 1, a heating circuit 400 and an auxiliary heating circuit 300 are connected to a hot water storage tank 2 in parallel with each other, and supply of hot water heated in the heating circuit 400 to the hot water storage tank 2 and supply of hot water heated in the auxiliary heating circuit 300 to the hot water storage tank 2 are executed simultaneously in parallel. In the case where there is a conflict between a heater operation request for instructing heater heating operation for supplying the hot water heated by an auxiliary heating heater to the hot water storage tank from the auxiliary heating circuit and a circulation operation request for instructing hot water circulation operation for circulating the hot water in the heating circuit and the hot water in the hot water storage tank in a state where waste heat is not recovered from a fuel cell, a heater side circulation pump is controlled in such a manner that the heater operation request is prioritized and the heater heating operation is performed without performing the hot water circulation operation.SELECTED DRAWING: Figure 1 【課題】温水循環運転及びヒータ加熱運転の競合時に好適に制御し、加熱能力の制御不能状態が生じるのを回避する。【解決手段】燃料電池システム１において、加熱回路４００及び補助加熱回路３００は、貯湯タンク２に互いに並列に接続されており、加熱回路４００で加熱された温水の貯湯タンク２への供給と、補助加熱回路３００で加熱された温水の貯湯タンク２への供給とを、同時並行して実行する。補助加熱ヒータにより加熱された温水を補助加熱回路から貯湯タンクへ供給するヒータ加熱運転を指示するヒータ運転要求と、燃料電池から排熱を回収しない状態で加熱回路内の温水と貯湯タンク内の温水とを循環させる温水循環運転を指示する循環運転要求と、が競合した場合、ヒータ運転要求を優先し、温水循環運転を行わずヒータ加熱運転を行うようにヒータ側循環ポンプを制御する。【選択図】図１